Roller skate



FIG. 1 is a left side elevational view of a roller skate, the right side elevational view thereof being identical;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a bottom plan view thereof.

The broken line showing of the boot in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a roller skate, as shown and described. 